JP6203191B2 - Liner to protect the adhesive - Google Patents

Description

  The present invention relates to the technical field of liners for protecting adhesives used, for example, for adhesive tapes. In particular, we propose a new liner characterized by an enhanced protective function against permeable substances. The invention further relates to an adhesive that is at least partially covered by a liner, as well as a method for protecting the adhesive and the use of getter material in the liner.

  Optoelectronic configurations are being used more frequently in merchandise than ever before or are on the verge of market introduction. Such configurations include organic or inorganic electronic structures such as organic, organometallic or polymeric semiconductors or combinations thereof. Depending on the desired application, the product in question is hard or soft in form and there is an increasing demand for flexible configurations. This type of configuration is often manufactured by printing techniques such as relief printing, gravure printing, screen printing or lithographic printing, or what is known as non-impact printing such as thermal transfer printing, ink jet printing or digital printing. However, in many cases, vacuum techniques such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma chemical or physical vapor deposition techniques (PECVD), sputtering, (plasma) etching or vapor deposition coating are used as well. . Patterning is generally performed through a mask.

  Examples of optoelectronic applications that are already on the market or of interest in terms of market potential include electrophoretic or electrochromic structures or displays, organic light emitting diodes or polymer light emitting diodes in readout and display devices or as illumination ( OLED or PLED) and also organic solar cells such as electroluminescent lamps, light emitting electrochemical cells (LEEC), dyes or polymer solar cells, inorganic solar cells, in particular based on eg silicon, germanium, copper, indium and selenium And thin film solar cells, organic field effect transistors, organic switching elements, organic optical amplifiers, organic laser diodes, organic or inorganic sensors, or other organic or inorganic RFID transponders.

  A recognized technical challenge for achieving sufficient lifetime and function of optoelectronic devices in the field of organic and inorganic optoelectronics, especially organic optoelectronics, is to protect the components they contain from permeate It is. A permeate is generally considered to be a gaseous or liquid material that can permeate and permeate and move through a solid. Thus, a large number of low molecular weight organic or inorganic compounds can be permeates, and water vapor and oxygen are particularly important in the context described herein.

  A variety of optoelectronic devices (especially when using organic materials) are sensitive to both water vapor and oxygen. Therefore, protection by encapsulation is required during the lifetime of the electronic device. Otherwise, there will be performance degradation over the application period. Otherwise, for example, the brightness of the light-emitting device components such as electroluminescent lamps (EL lamps) and organic light-emitting diodes (OLEDs) is dramatically reduced in a short period of time, resulting in an electrophoretic display (EP display). In this case, the contrast may decrease dramatically in a short time, or in the case of a solar cell, the efficiency may decrease dramatically in a short time.

  Thus, in the field of inorganic and especially organic optoelectronics, there is a high demand for flexible adhesive bonding solutions that present barriers to permeates such as oxygen and / or water vapor. Many approaches to such adhesive bonding solutions can already be found in the prior art.

  That is, with relative frequency, epoxide-based liquid adhesives and adhesive binders are used as barrier adhesives as described, for example, in WO 98/21287 A1, US Pat. No. 4,051,195 and US Pat. No. 4,552,604. ing. Their main field of use is edge bonding in rigid devices as well as moderately flexible devices. Curing is effected by heat or by UV irradiation.

  However, the use of these liquid adhesives has a series of undesirable effects as well. For example, low molecular weight components (VOC: volatile organic compounds) can damage the delicate electronic structure of the device and complicate manufacturing. Furthermore, the adhesive must be applied to each component of the device in an expensive and inconvenient procedure. In order to ensure accurate positioning, it is necessary to provide expensive dispensers and fixing devices. Furthermore, the nature of this application has the effect of hindering rapid continuous operation. In the laminating process that is required thereafter, the low viscosity may hinder the achievement of the predetermined film thickness and bond width.

  One option is to use a pressure sensitive or hot melt adhesive to seal the optoelectronic structure. Of the pressure sensitive adhesive (PSA), it is preferable to use one that can be crosslinked by introduction of energy (for example, actinic radiation or heat) after adhesion. These types of adhesives are described, for example, in US Patent Application Publication No. 2006 / 0100299A1 and International Application Publication No. 2007 / 088781A1. Their advantage is in particular the fact that the barrier effect of the adhesive can be improved by crosslinking.

  Also known in the prior art is the use of hot melt (HM) adhesives. Often used herein are copolymers of ethylene, such as ethylene ethyl acetate (EEA), ethylene acrylic acid copolymer (EAA), ethylene butyl acrylate (EBA), ethylene Methyl acrylate (EMA). Crosslinkable ethylene / vinyl acetate (EVA) copolymers are commonly used, particularly for solar cell modules based on silicon wafers. Crosslinking is performed under pressure and at a temperature above about 120 ° C. during the sealing operation. For many optoelectronic structures based on organic semiconductors or manufactured in thin film processes, this operation is detrimental as a result of mechanical loads imposed by high temperatures and pressures.

  Hot melt additives based on block copolymers or functionalized polymers are, for example, WO 2008/036707 A2, WO 2003/002684 A1, JP 2005-298703 and US patents. This is described in Japanese Patent Application Publication No. 2004 / 0216778A1. The advantage of these adhesives is that the adhesive itself introduces any material (or very little material) that harms the composition itself into the encapsulated composition, The problem is particularly relevant for reactive liquid adhesive systems, especially those based on acrylate or epoxy resins. Considering the large number of reactive groups, these systems have a relatively high polarity, so water is present in particular in them. The amount is in the range of less than 100 ppm to 1%. Especially for this reason, such liquid adhesives are mainly used as edge sealants for electronic devices that are not in direct contact with active electronic materials.

  Another possibility to counter the problem of entrained permeate is to further include an absorbent material (referred to as a getter) within the capsule, which getter penetrates or disperses from the adhesive or Bind other permeates (eg, by absorption or adsorption). This type of approach is described in particular in EP 1407818 A1, US 2003/0057574 A1 and US 2004-0169174 A1.

  Another means is to provide an adhesive and / or a substrate and / or an electronic structure cover having such bonding properties, as described, for example, in WO 2006/036393 A2, DE102009036970A1 and DE102009036968A1.

  In addition, use of raw materials with a particularly low permeate content and ensure that the adhesive does not contain permeable substances during production or before application, for example by heat drying, vacuum drying, freeze drying or mixing of getters. Is possible. The disadvantages of such methods are the long drying times and possibly high or low drying temperatures that can adversely affect the adhesive or initiate chemical reactions such as cross-linking. Furthermore, the operation of mixing and subsequently removing the getter is expensive and inconvenient.

  If such adhesive-related measures are taken to reduce the introduction of harmful permeable materials into the structure to be protected, the resulting properties should be minimized as much as possible until the adhesive is used. It is necessary to maintain at the limit. Thus, for example, an adhesive made in a particularly anhydrous procedure must be protected from water uptake from the environment.

  This problem is usually solved by providing the adhesive with a package that resists or at least impedes permeation. The liquid adhesive is generally dispensed into a corresponding container made of metal, for example. The adhesive tape is often bonded to a flexible pouch made from a permeation inhibiting material such as a polyethylene film or a laminate of aluminum and polyester film. Also, the packaging material itself should be largely free of permeate that may be released to the contents side.

  In order to address weaknesses in the imperviousness of the packaging or to ensure rapid binding of the permeates contained, getters may also include getters in packaging in the form of pouches filled with silica gel or zeolite There are many. This getter is generally not in direct contact with the contents. Special disadvantages of this method are increased costs and inconvenience of packaging.

  A specific problem arises in the packaging of sheet adhesives, ie adhesive tapes and adhesive sheets: when these are laminated or rolled into a certain shape to form a roll, they remain in the packaging A gas (such as air) that is not in an exchanged state with the rest of the gas space is included. Thus, undesired permeates present, such as water vapor, may not reach the getter material located within the package and can migrate to the adhesive. In addition, such adhesive tapes generally comprise a temporary liner material and often also a carrier material. These materials may also contain undesirable permeates, which can easily penetrate into the adhesive, especially considering the large contact area with the adhesive. Getter pouches and getter pads introduced into the package may reliably capture and not bind these permeates. The complete removal of liner material and carrier material from unwanted permeates, for example by drying, is cumbersome, costly and inconvenient.

  EP 2078608 A1 describes the use of liner materials with special permeation barriers. However, this approach is not effective for the permeate present in the liner or contained between the liner and the adhesive.

  Therefore, there is a continuing need for liners that reliably protect sheet adhesives from the effects of permeates.

International Publication No. 98/21287 Pamphlet US Pat. No. 4,051,195 U.S. Pat. No. 4,552,604 US Patent Application Publication No. 2006/0100299 International Application Publication No. 2007/08871 Pamphlet International Application Publication No. 2008/036707 Pamphlet International Application Publication No. 2003/002684 Pamphlet JP 2005-298703 A US Patent Application Publication No. 2004/0216778 European Patent Application No. 1407818 US Patent Application Publication No. 2003/0057574 US Patent Application Publication No. 2004-0169174 International Publication No. 2006/036393 Pamphlet German Patent Application Publication No. 102009036970 German Patent Application Publication No. 102009036968 European Patent Application No. 2078608

  Accordingly, it is an object of the present invention to provide a liner that protects the adhesive from the permeate contained in the course of winding or lamination and other processing steps as well as permeate originating from the environment. This ensures that in the case of products such as adhesive tapes, which mostly comprise an adhesive layer that is free of permeation, this adhesive layer should remain free of permeation during storage and transport. In fact, the adhesive layer is also free of residual permeate.

  The achievement of this object is obtained by providing the basic concept of the invention, i.e. the liner is provided with a getter material contained therein.

  Accordingly, the present invention first comprises a liner for protecting an adhesive comprising at least one non-stick release layer and at least one getter material capable of sorbing at least one permeable material. Provided, wherein the getter material is present as a dispersed phase in at least one layer of the liner. This type of liner advantageously prevents permeation of permeate from the environment into the adhesive to be protected, and is also present between the permeate present in the adhesive and between the liner and the adhesive. Can also be combined. Thus, it is not necessary to pretreat the adhesive itself or the product containing the adhesive separately (eg by drying).

FIG. 1 shows the structure of a liner of the present invention having an intermediate layer comprising a getter material. FIG. 2 shows the structure of the liner of the present invention having an intermediate layer comprising a getter material.

  Adhesive tapes coated with an adhesive on one or both sides are usually wound up in the form of an Archimedes spiral at the end of the manufacturing process. In order to prevent the adhesives in the double-sided adhesive tape from contacting each other, or in the case of single-sided adhesive tapes, the adhesive tape is a liner that is wound together with the adhesive tape. Lined before being rolled up with the material (also called release material). The person skilled in the art knows such liner materials merely as a liner or release liner. In addition to lining single-sided or double-sided adhesive tapes, liners are also used to line pure adhesive (adhesive transfer tape) and adhesive tape parts (eg labels).

  Thus, a liner is a coating material that has an anti-adhesive (non-tacky) surface and is applied directly to the adhesive for temporary protection of the adhesive, and generally just prior to application of the adhesive Can be removed by simple peeling.

  These release liners also ensure that the adhesive is not contaminated prior to use. It should be noted that the release liner can be adjusted through the nature and composition of the release material to allow the adhesive tape to be rewound with the desired force (easy or difficult). Furthermore, in the case of adhesive tapes coated with adhesive on both sides, the release liner ensures that the correct side of the adhesive is first exposed during unwinding.

  The liner is not part of the adhesive tape, but merely assists in its manufacture, storage or further processing. Also, unlike adhesive tape carriers, the liner is not tightly bonded to the adhesive layer; instead, assembly is only temporary and not permanent.

  The liner of the present invention contains at least one non-stick release layer. According to the present invention, the term “tack free” refers to the adhesive to which the release layer is coated rather than the adhesion to the carrier material belonging to the intended application substrate and, optionally, the adhesive during its use. Represents the technical idea of having low adhesion.

  The material of the non-stick release layer is preferably selected from the group consisting of silicone, fluorinated silicone, silicone copolymer, wax, carbamate, fluoropolymer and polyolefin or a mixture of two or more of the above substances. Particularly preferably, the material of the non-stick release layer is selected from silicones and polyolefins.

  The system forming the non-tacky release layer is preferably formulated in such a way that there is essentially no diffusion of the non-tacky substance into the adhesive. Analytical, it may still be possible to detect material from the non-stick coating, but these may be due to mechanical wear.

  The non-stick release layer preferably has substantially no vapor pressure at room temperature.

  The non-sticking release layer is preferably made of a silicone system. Such silicone systems are preferably produced using crosslinkable silicone systems. These include a mixture of a crosslinking catalyst and a so-called thermosetting condensation crosslinking or addition crosslinking polysiloxane. As crosslinking catalysts for condensation-crosslinking silicone systems, tin compounds such as dibutyltin diacetate are frequently present in the composition.

Silicone release agents based on addition crosslinking can be cured by hydrosilylation. These release agents typically include the following components:
Alkenylated polydiorganosiloxanes (particularly linear polymers having terminal alkenyl groups),
-Polyorganohydrogensiloxane crosslinker and-Hydrosilylation catalyst.
Established catalysts (hydrosilylation catalysts) for addition-crosslinking silicone systems include, for example, platinum or platinum compounds such as karsted catalysts (Pt (0) complex compounds).

Thus, thermosetting release coatings are often multicomponent systems that typically consist of the following components:
(A) A linear or branched dimethylpolysiloxane composed of about 80 to 200 dimethylpolysiloxane units and terminated with vinyldimethylsiloxy units at the chain ends. Typical examples are, for example, solventless addition-crosslinkable silicone oils having terminal vinyl groups, such as Dehesive® 921 or 610, both commercially available from Wacker-Chemie GmbH;
(B) A linear or branched cross-linking agent typically consisting of a methylhydrogen siloxy unit and a dimethylsiloxy unit and having a chain end filled with either a trimethylsiloxy group or a dimethylhydrogensiloxy group. Typical examples of this class of materials are, for example, hydrogen polysiloxanes with highly reactive Si-H groups, such as the crosslinkers V24, V90 or V06, commercially available from Wacker-Chemie GmbH;
(C) A silicone MQ resin having not only a trimethylsiloxy unit typically used but also a vinyldimethylsiloxy unit as an M unit. Typical examples of this group are, for example, the peel force regulators CRA® 17 or CRA® 42 commercially available from Wacker-Chemie GmbH;
(D) For example, a silicone-soluble platinum catalyst such as a platinum-divinyltetramethyldisiloxane complex that is generally called a calsted complex and is commercially available, for example, from Wacker-Chemie GmbH under the trade name Katalystor OL.

  Also photoactive catalysts known as photoinitiators, UV curable cationic cross-linked siloxanes based on epoxides and / or vinyl ethers, and / or UV curable free radical cross-linkable siloxanes such as acrylate modified siloxanes It is also possible to use together. Similarly, an electron beam curable silicone acrylate can be used. Such systems can also further include additional additives such as stabilizers and flow control aids depending on their intended use.

Silicone-containing systems are commercially available from, for example, Dow Corning, Wacker or Rohm & Haas.
An example is Dehesive® 914 containing vinyl polydimethylsiloxane, crosslinker V24, methylhydrogen polysiloxane and catalyst OI, platinum catalyst in polydimethylsiloxane. This system is available from Wacker-Chemie GmbH.
Further, what can be used is, for example, addition-crosslinkable silicone release system Dehesive (registered trademark) 940A having a related catalyst, which is commercially available from Wacker-Chemie, which is in an uncrosslinked state. It is applied and subsequently crosslinked in the applied state.

  Of the above silicones, addition-crosslinking silicones have the greatest economic significance. However, an undesired feature of these systems is that they are susceptible to catalyst poisons such as heavy metal compounds, sulfur compounds and nitrogen compounds (in this regard, “Chemiche Technik, Proposse and Product” by R. Dittmeyer et al. , Vol. 5, 5th edition, Wiley-VCH, Weinheim, Germany, 2005, Section 6-5.3.2, page 1142. In general, it is true that an electron donor may be considered a platinum poison (A. Colas, Silicone Chemistry Overview, Technical Paper, Dow Corning). Therefore, among these compounds, phosphorus compounds such as phosphines and phosphites are considered platinum poisons. The presence of the catalyst poison means that the cross-linking reaction between the various components of the silicone release coating material no longer occurs or only slightly occurs. Thus, in the production of anti-adhesive silicone coatings, the presence of catalyst poisons, in particular platinum poisons, is strictly avoided. Accordingly, the getter material present in the liner of the present invention is preferably not a platinum poison.

  Particular embodiments of silicone systems are polysiloxane block copolymers having urea blocks, such as those available from Wacker under the trade name “Geniomer” or release systems comprising fluorosilicones, which are Especially used in adhesive tapes featuring silicone adhesives.

The polyolefin-based release layer can be made of a thermoplastic, inelastic or elastic material. For example, such a release layer can be based on polyethylene. For this purpose, it is possible to use a polyethylene of about 0.86 g ^/ cm 3 full density range achievable in ~ 1 g / cm ^3. For a given application, preferably lower density polyethylene is suitable. This is because they often produce lower peel forces.

  Further, the release layer having elastic characteristics can be made of an olefin-containing elastomer. Examples include both random copolymers and block copolymers. Examples of block copolymers include ethylene-propylene rubber, butyl rubber, polyisobutylene, ethylene block copolymers, and partial and complete hydrogenations such as styrene-ethylene / butylene and styrene-ethylene / propylene block copolymers Examples thereof include styrene-diene block copolymers.

  A suitable release layer can also be provided by an acrylate copolymer. A preferred embodiment of this variant is an acrylate polymer having a static glass transition temperature (midpoint Tg as determined by differential thermal analysis) below room temperature. These polymers are typically crosslinked. Crosslinking is either chemical or physical and can be of the type realized with, for example, block copolymers.

  The at least one non-stick release layer of the liner of the present invention preferably has a layer thickness of 0.5 to 500 μm, more preferably 1 μm to 250 μm, for example 1.5 to 100 μm. These layer thickness ranges are in some cases outside of conventional layer thicknesses, particularly those in the range of about 500 nm to 3 μm, taking into account the possibility of the getter material being present in the release layer.

  The non-stick release layer can be applied directly from the solution, emulsion or dispersion by means of an application bar. In this case, the solvent, emulsification medium or dispersion medium to be used can then be evaporated with a commercially available dryer. Solvent-free coating with a nozzle or roll coating unit is also suitable.

  According to the present invention, a non-adhesive layer can also be printed. Suitable for this purpose according to the prior art are relief, gravure and screen printing methods. Here, it is preferable to employ a rotary printing method. Furthermore, the non-stick coating can be applied by spraying. This can optionally be done electrostatically by a rotary spray method.

  The material of the non-stick release layer and optionally the optional carrier layer material need not take the form of a homogeneous material, but can alternatively consist of a mixture of two or more materials. Therefore, in order to optimize the properties and / or processing, these materials are in each case resins, waxes, plasticizers, fillers, pigments, UV absorbers, light stabilizers, aging inhibitors, crosslinkers. Can be blended with one or more additives such as crosslinking accelerators, antifoaming agents, degassing agents, wetting agents, dispersion aids, rheological additives or elastomers.

  In the simplest case, the liner of the invention consists only of a non-stick release layer comprising at least one getter material. In a further embodiment, the liner of the present invention includes at least one carrier layer. In this case, the non-stick release layer may be applied directly to the carrier layer and may at least partially cover the layer. Typically, the tack-free release layer is applied in the form of a continuous (uninterrupted) outermost layer that is at least on the side of the carrier material facing the adhesive.

  The liners of the present invention can also have at least partially non-stick surfaces on both sides, regardless of the presence of the carrier layer, and the surfaces can be the same or different.

  The carrier material for the liner can be paper, plastic-coated paper or film / foil, preferably film / foil, particularly dimensionally stable polymer film or metal foil. Thus, the at least one carrier layer is preferably a polyester, in particular polyethylene terephthalate, such as biaxially stretched polyethylene terephthalate, or a polyolefin, in particular polybutene, cycloolefin copolymer, polymethylpentene, polypropylene or polyethylene, such as uniaxially stretched polypropylene, It consists of biaxially stretched polypropylene or biaxially stretched polyethylene. Polyester films have the advantages of having good barrier properties, ensuring temperature stability, and contributing to improved mechanical stability. Thus, particularly preferably, at least one carrier layer of the liner according to the invention consists of a polyester film, for example biaxially oriented polyethylene terephthalate.

  Paper or nonwoven webs are other suitable carrier materials.

  In a preferred embodiment, the liner of the present invention comprises a barrier layer for one or more specific permeates, in particular for water vapor and oxygen. According to the present invention, it is further preferred that the liner comprises at least one carrier layer, which carrier layer has a barrier function against one or more specific permeates. This kind of barrier function can consist of organic or inorganic materials. Carrier materials having a barrier function are comprehensively described in EP 2078608.

  Particularly preferably, the liner of the present invention comprises at least one inorganic barrier layer. Suitable inorganic barrier layers are particularly well deposited under metal (especially by evaporation, CVD, PVD, PECVD) or under atmospheric pressure (atmospheric plasma, reactive corona discharge or fire). Including metal compounds such as metal oxides, metal nitrides or metal hydrides (for example, flame pyrolysis), examples include nitrides of silicon, boron, aluminum, zirconium, hafnium or tellurium, and silicon, boron, aluminum, zirconium, hafnium Or an oxide of tellurium and indium tin oxide (ITO). Likewise suitable are layers of the above variant which are doped with further elements. Metal foil is also a suitable barrier layer. Preferably, the liner of the present invention comprises an aluminum foil that advantageously functions as a carrier material having a barrier function, for example.

Particularly preferably, the liner according to the invention comprises at least one carrier layer and at least one barrier layer for one or more specific permeates, the barrier layer and the carrier layer being in the form of a layer directly following each other. . A particularly suitable method for applying the inorganic barrier layer is a high-power impulse magnetron sputtering method or an atomic layer deposition method. By this means, it is possible to realize a layer particularly resistant to transmission while applying a low temperature load to the carrier layer. Is possible. (WVTR) and / or <1 cm ³ / (m ^{2 *} D ^* bar) oxygen for <1 g / (m ^{2 *} d) of water vapor in a carrier layer having a barrier function or an assembly of a carrier layer and a barrier layer An (OTR) permeation barrier to is preferred, where this value is based on the thickness of the respective carrier layer used in the liner, in other words not standardized to a specific thickness. WVTR is measured at 38 ° C. and 90% relative humidity according to ASTM F-1249, and OTR is measured at 23 ° C. and 50% relative humidity according to Part 3 of DIN-53380.

  The liner of the present invention comprises at least one layer comprising a getter material capable of sorbing at least one permeable material.

  “Sorption” refers to “adsorption”, which is the process of taking a substance or substances by another substance (according to the invention by a getter material). Sorption of the permeable material by the getter material can be performed, for example, by absorption or adsorption, and adsorption can occur in both chemisorption and physical adsorption forms.

A “permeable material” is a material that can penetrate into the adhesive to be protected and then saturate it as a gaseous or liquid material, or in some cases as a solid material. This type of material is referred to above and is hereinafter referred to as “permeate”. The permeate may come from the adhesive itself or the environment, for example the carrier material of the adhesive tape coated with the adhesive. Often, low molecular weight organic compounds such as solvent residues, residual monomers, oil, resin components, plasticizers or water are produced from the adhesive or adhesive tape itself. The environment is often a source of water, volatile organic compounds (VOC), low molecular weight hydrocarbons and oxygen. Substances considered to be “permeable substances” include in particular:
Acetonitrile, 1-butanol, chlorobenzene, chloroform (trichloromethane), cyclohexane, diethyl ether, 1,4-dioxane, glacial acetic acid (acetic acid), acetic anhydride, ethyl acetate (ethyl acetate, ethyl ethanoate), n-butyl acetate Ester (n-butyl acetate), t-butyl acetate (t-butyl acetate), ethanol, methanol, n-hexane, n-heptane, 3-hexanone, 2-propanol (isopropanol), 3-methyl-1-butanol (Isoamyl alcohol), methylene chloride (dichloromethane), methyl ethyl ketone (butanone), methyl isobutyl ketone, nitromethane (nitrocarbol), n-pentane, 2-pentanone, 3-pentanone, petroleum ether (light benzine), benzine, pro Nord, pyridine (azine), t-butyl methyl ether, tetrachloroethene (perchloroethene), tetrahydrofuran, toluene, trichloroethane, triethylamine, xylene, oxygen, methane, ethane, propane, propene, butane, butene, carbon dioxide, ozone , Sulfur dioxide, water.

  A “getter material” is a material that can incorporate at least one permeable substance in the sense of the process defined above as “sorption”. Thus, getter materials could also be referred to as “adsorbents” or “sorbents”. The getter material is preferably capable of sorbing at least water.

  The phrase “present as a dispersed phase in at least one of the liner layers” means that the getter material is present in finely divided form within the liner layer or layer of interest. In principle, there are no restrictions on the shape and size of the getter material particles. Depends on limitations caused by configuration and liner function. The characteristics of “present as dispersed phase” include not only the molar dispersion of the getter material, ie the true (molecular) solution of the getter material in the material of the layer in question, but also the primary particles of the getter material, aggregates of the getter material and Examples also include dispersions of aggregates of getter materials.

  The feature "present as a dispersed phase in at least one of the layers of the liner" further means that the getter material does not form a separate continuous layer, but instead generally exists in the form of a plurality of dispersed particles. . On the other hand, this does not mean that there must be an ideal or statistical distribution of getter material particles in the layer material. Indeed, for example, the getter material particles may be concentrated in specific areas within the layer, and the specific areas of the getter-containing layer of the liner may not contain getter material.

  The distribution of getter material as a dispersed phase in the liner layer has the advantage that the specific surface area for permeate uptake is greater than that of the continuous layer over the continuous independent getter material layer, It makes it possible to achieve a higher capture capacity.

  The size of the particles of the getter material is in principle limited by the thickness requirements of the layer containing them in each case, for example a non-stick release layer or a carrier layer. Thus, although it is possible to consider about 200 μm as the upper limit of the size of the particles, the getter material is preferably used in the form of particles having a particle size of 50 μm or less.

  At least one getter material is present in at least one of the layers of the liner. This means that a plurality of liner layers, such as a carrier layer and a non-stick release layer, and possibly even additional layers, can contain the same or different getter materials.

  The getter material is preferably present in the form of particles with a particle size distribution in which up to 1% by volume of the getter material exceeds the average layer thickness of the layer containing the getter material. This has the advantage that the getter particles do not protrude from the layer and therefore do not have a significant adverse effect on the surface properties. In one particularly preferred embodiment, the total getter material present in the liner of the present invention is present in a particle size distribution in which up to 1% by volume of the getter material exceeds the average layer thickness of the layer containing the getter material.

  “Particles” refer to primary particles, aggregates and aggregates of one or more getter materials in DIN 53206-1: 1972-08. “Particle size” means the maximum range of particles. The particle size is preferably determined by laser diffraction according to ISO 13320 (in this case the aggregates are dispersed in the dispersion step but the aggregates are not dispersed), but other methods known to those skilled in the art are also suitable.

  Particularly preferably, all of the getter materials are present in nanoscale form, which means that the maximum dimension in at least one dimension is less than 500 nm, very preferably less than 200 nm, for example less than 100 nm. .

  Examples of this type of getter material include dispersed pyrolytic silica such as Aerosil manufactured by Evonic, calcium oxide nanopowder manufactured by Sigma-Aldrich, and calcium chloride CA-CI-02-NP manufactured by American Elements (Los Angeles). Nanozeolite LTA or FAU from Nanoscape (Planegg-Martinsried) or Nanoscale zeolite Lucidot NCL40 from Clariant (Frankfurt).

  In a further preferred embodiment, the getter material is present in the form of particles with a particle size distribution in which at least 10% by volume exceeds the average layer thickness of the layer comprising the getter material. This can result in a rough surface and can improve the adhesion of the various layers in the liner layer assembly or reduce the peel force of the liner. This is because the contact area with the adhesive is reduced. When these particles are placed in a release layer, they are in relatively direct contact with the adhesive tape because they are coated with a relatively small area, thus binding the permeate much more efficiently. be able to. Particularly preferably, the total getter material present in the liner according to the invention is present in a particle size distribution in which at least 10% by volume exceeds the average layer thickness of the layer comprising the getter material.

  Examples of suitable getter materials are: cobalt chloride, calcium chloride, calcium bromide, lithium chloride, lithium bromide, magnesium chloride, barium perchlorate, magnesium perchlorate, zinc chloride, zinc bromide, Salts of aluminum sulfate, calcium sulfate, copper sulfate, barium sulfate, magnesium sulfate, lithium sulfate, sodium sulfate, cobalt sulfate, titanium sulfate, sodium dithionite, sodium carbonate, sodium sulfate, potassium disulfite, potassium carbonate, magnesium carbonate, etc. Filler silicates such as montmorillonite and bentonite; metal oxides such as barium oxide, calcium oxide, iron oxide, magnesium oxide, sodium oxide, potassium oxide, strontium oxide, aluminum oxide (activated alumina), titanium dioxide; Carbon nanotubes, activated carbon, phosphorus pentoxide, and silanes; easily oxidizable metals such as iron, calcium, sodium and magnesium; for example, calcium hydride, barium hydride, strontium hydride, sodium hydride, And metal hydrides such as lithium aluminum hydride; hydroxides such as potassium hydroxide and sodium hydroxide; metal complexes such as aluminum acetylacetonate; silica such as silica gel; diatomaceous earth; zeolites; Absorbents such as polyolefin copolymers, polyamide copolymers, PET copolyesters, monocarboxylic and polycarboxylic acid anhydrides such as acetic anhydride, propionic anhydride, butyric anhydride, or methyltetrahydrophthalic anhydride, or For example, usually Other absorbent agents based on hybrid polymers used in conjunction with a catalyst such as Baltic; for example, weakly crosslinked polyacrylic acid, polyvinyl alcohol, ascorbate, glucose, organic absorbents such as gallic acid and unsaturated fats. Also particularly advantageous for oxygen bonding are organometallic oxidation additives based on chelate-forming amines and transition metal complexes, particularly in combination with oxidizable substrate materials. According to the invention, it is also possible to use a mixture of two or more getter materials.

Depending on their function, the getter material is preferably used as a material which is substantially free of permeate, eg free of water. This distinguishes between getter materials and similar materials used as fillers. Thus, for example, silica is often used as a filler in the form of pyrogenic silica. However, if the filler is stored normally under ambient conditions, it already takes up water from the environment and can no longer function as a getter material to the extent that it is technically available. Only dry or dry-stored silica can be used as a getter material. However, according to the present invention, it is also possible to use materials that are already partially complexed with the permeate, for example CaSO ₄ ^* 1 / 2H ₂ O (calcium sulfate hemihydrate ) Or, by definition, partially hydrogenated silica that exists as a compound of the general formula (SiO ₂ ) _m ^* nH ₂ O.

“Silane” means _a compound of the general formula R _a —Si—X _4-a or a partial condensate thereof. In formula, a is an integer of 0-3, Preferably it is 0 or 1. X is a hydrolyzable group, for example preferably a halogen atom, in particular chlorine, for example an alkoxy group such as a methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy or t-butoxy group or an acetoxy group. . Other examples of hydrolyzable groups known to those skilled in the art can be used for the purposes of the present invention as well. When two or more substituents X are present, these may be the same as or different from each other. R represents an optionally substituted hydrocarbon group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl group, pentyl group and branched isomers thereof, hexyl group and branched groups thereof. Isomers, heptyl group and its branched isomer, octyl group and its branched isomer, nonyl group and its branched isomer, decyl group and its branched isomer, undecyl group and its branched isomer, dodecyl group and its branched isomer , Tetradecyl group and its branched isomer, hexadecyl group and its branched isomer, octadecyl group and its branched isomer or eicosyl group and its branched isomer. Furthermore, examples of the hydrocarbon group include cyclic and / or aromatic components. Their representative structures are cyclohexyl, phenyl and benzyl groups. The one or more hydrocarbon groups R optionally include one or more heteroatom-containing substituents such as, for example, amino groups, aminoalkyl groups, glycidyloxy groups, (meth) acryloyloxy groups. When two or more substituents R are present, they may be the same or different.

  The silane that can be used as the getter material is preferably N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane. Methoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, N- (2-aminoethyl) -3-aminopropyldimethoxymethylsilane, (N-butyl) -3-aminopropyltrimethoxysilane 3- (N-ethylamino) -2-methylpropyltrimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, 4-amino-3,3-dimethylbutyldimethoxymethylsilane, (N-cyclohexyl) ) Aminomethyldimethoxymethylsilane, (N-cyclohexane) Sil) aminomethyltrimethoxysilane, (N-phenyl) -3-aminopropyltrimethoxysilane, (N-phenyl) aminomethyldimethoxymethylsilane, (N-benzyl-2-aminoethyl) -3-aminopropyl-tri Methoxysilane, [2- (N-benzyl-N-vinylamino) ethyl] -3-aminopropyltrimethoxysilane hydrogen chloride, [2- (N-benzyl-N-vinylamino) ethyl] -3-aminopropyltri Methoxysilane, bis (3-propyltriethoxysilyl) amine, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (2-methoxyethoxy) silane, vinyltriisopropoxysilane, vinyldimethoxymethylsilane, vinyltriacetoxysilane, 3 -Triethoxysilylpro Succinic anhydride, 3-glycidyloxypropyl-trimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3-glycidyloxypropyldiethoxymethylsilane, 3 -Methacryloyloxypropyl-trimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropyl-triisopropoxysilane, 3-methacryloyloxypropyldimethoxymethylsilane, 3-methacryloyloxypropyldiethoxymethylsilane, 3- Chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane , Isocyanatomethyltrimethoxysilane, isocyanatomethyldimethoxymethylsilane, tris [3- (trimethoxysilyl) propyl] isocyanurate, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 2-hydroxy- 4- (3-triethoxysilylpropoxy) benzophenone, 4- (3′-chlorodimethylsilylpropoxy) benzophenone, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyldimethoxymethylsilane, bis (3-triethoxysilylpropyl) Disulfane, bis (3-triethoxysilylpropyl) tetrasulfane, bis (triethoxysilylpropyl) polysulfane and octadecylaminodimethyltrimethoxysilylpropyl ammonium Selected from the group consisting of um chlorides.

The getter material is preferably cobalt chloride, calcium chloride, calcium bromide, lithium chloride, lithium bromide, magnesium chloride, barium perchlorate, magnesium perchlorate, zinc chloride, zinc bromide, aluminum sulfate, calcium sulfate, Copper sulfate, barium sulfate, magnesium sulfate, lithium sulfate, sodium sulfate, cobalt sulfate, titanium sulfate, sodium carbonate, sodium sulfate, potassium carbonate, magnesium carbonate, and diatomaceous earth, silicic acid (silica), zeolite, filler silicate, and iron Calcium, sodium, magnesium, barium oxide, calcium oxide, iron oxide, magnesium oxide, sodium oxide, titanium dioxide, potassium oxide, strontium oxide, activated aluminum oxide, and carbon nanotubes, activated carbon, lithium pentoxide Silane, calcium hydride, barium hydride, strontium hydride, sodium hydride, and lithium aluminum hydride, potassium hydroxide, sodium hydroxide and aluminum acetylacetonate, and polyolefin copolymers, polyamide copolymers, PET copolyester,
Acetic anhydride, propionic anhydride, butyric anhydride, methyltetrahydrophthalic anhydride,
Polyacrylic acid and polyvinyl alcohol (because these materials are very suitable as water getters)
Selected from the group consisting of:

  For oxygen binding, the getter material is preferably iron, sodium dithionite, barium oxide, iron (II, III), carbohydrazide, activated aluminum oxide, zeolite, activated carbon, sulfite, ascorbate, hydrazine , Morpholine, 2-butanone oxime, diethylhydroxylamine, glucose, gallic acid, unsaturated oils, chelating amines and organometallic oxidation additives based on transition metal complexes, preferably oxidizable groups Used in combination with materials.

  Particularly preferably, the getter material is cobalt chloride, calcium chloride, calcium bromide, lithium chloride, lithium bromide, magnesium chloride, barium perchlorate, magnesium perchlorate, zinc chloride, zinc bromide, aluminum sulfate, calcium sulfate. , Copper sulfate, barium sulfate, magnesium sulfate, lithium sulfate, sodium sulfate, cobalt sulfate, titanium sulfate, sodium carbonate, sodium sulfate, potassium carbonate, zeolite, calcium, magnesium, barium oxide, calcium oxide, magnesium oxide, sodium oxide, oxidation Potassium, strontium oxide, activated carbon, phosphorus pentoxide, silane, calcium hydride, barium hydride, strontium hydride, sodium hydride and lithium aluminum hydride, potassium hydroxide, sodium hydroxide, anhydrous Acid, propionic anhydride, butyric anhydride, is selected from methyl-tetrahydrophthalic anhydride, and carbodiimides as well as the group consisting of a mixture of two or more of the above materials. These materials also have a high adsorption capacity for at least one of the permeates, especially water.

“Carbodiimide” is a compound of the general formula R ¹ —N═C═N—R ² , wherein R ¹ and R ² are organic groups, particularly alkyl or aryl groups which may be the same or different. That is.

  The getter material very preferably consists of calcium chloride, calcium oxide, boron trioxide, sodium sulfate, potassium carbonate, copper sulfate, magnesium perchlorate, magnesium sulfate and zeolite, and a mixture of two or more of the above substances. Selected from the group. These getter materials can be easily incorporated into the relevant layers of the liner, exhibit high adsorption capacity, and offer the benefit of being renewable getter materials. These refer to substances that, under certain conditions, can release the permeate that has been taken up, for example water again, so that a new permeate can be taken up. This makes it possible for the getter-containing liner to obtain a method in which most of the permeate incorporated prior to that point is released prior to contact with the adhesive, where this release is For example, it is achieved by drying. As a result, advantageously, the full getter capacity is available when using a liner.

  The getter material is selected not only from calcium oxide, calcium sulfate, calcium chloride and zeolite, but also from mixtures of two or more of the above substances. These materials have a particularly high capacity for water and other permeate uptake, are reproducible for very large parts, and are significantly incorporated into liners such as carrier layers or non-stick release layers. And has little or no effect on the function of these layers.

  In one particular embodiment of the liner of the present invention, the getter material is selected from calcium oxide, calcium, iron, barium, lithium chloride and cobalt chloride. These materials draw conclusions about the permeate content of adhesives through changes in their optical properties in that, for example, they achieve a change from white to a transparent appearance due to increased water uptake. Make it possible. Thus, as long as the free getter capacity can still be recognized based on the appearance of the liner, this can be interpreted as indicating that the permeate has not yet diffused or, at best, less diffused into the adhesive to be protected. For example, metallic calcium loses its metallic opaque appearance and becomes increasingly transparent. Cobalt chloride changes its color from blue to pink by water uptake. The getter material is in particular calcium oxide.

  In a further preferred embodiment, the getter material binds the permeate by chemisorption. This process generally occurs more slowly than physisorption because of the higher activation energy. Here, a known example is calcium oxide, which is converted to calcium hydroxide by the permeate water. As a result of the relatively slow reaction, there is the possibility of easily handling the getter material in the atmosphere without losing a significant portion of the uptake capacity.

The getter material is preferably dispersed in a molecular form in the matrix material. This is because both transparency and surface roughness are adversely affected to a lesser extent by comparison with the particles. Particularly used for this purpose are metal complexes and organometallic compounds, preferably organometallic Lewis acids which do not form alcohols by reaction with water. This is preferred because alcohol can cause degradation of the organic electronic structure like water. Examples of such compounds include Al (C ₂ H ₅ ) ₃ , Al (C ₄ H ₉ ) ₃ , B (C ₄ H ₉ ) ₃ , Zn (C ₄ H ₉ ) ₂ , Al (t-butyl) ₃ , Ti (t-butyl) ₄ , Mg (t-butyl) ₂ , Al (C ₄ H ₉ ) ₂ (N (C ₆ H ₅ ) ₂ ), Al (C ₄ H ₉ ) (N (C ₆ H ₅ ) ₂ ) ₂ and other examples described in US 2006/0087230.

  Even more preferred are getter materials with high activity even at low permeate concentrations. Therefore, for water as permeate, it is preferable to use a getter material with a saturated aqueous solution that produces a relative humidity of less than 20% at 20 ° C. and a pressure of 1013 mbar. In view of activity at low permeate concentrations, the getter material is preferably selected from sodium hydroxide, potassium hydroxide, lithium bromide, zinc bromide, lithium chloride, calcium bromide, lithium iodide and calcium acetate. The

  The liner of the present invention preferably includes a getter material in a non-stick release layer. In this case, the getter material present in the release layer is located in the immediate vicinity of the adhesive to be protected, so any permeate present in the release layer itself, the permeate contained between the adhesive and the liner, More effective bonding of the permeate still present in the adhesive can be performed. Surprisingly, it has been found that despite the release material being filled with a getter material, the tack free properties are only negligibly affected. Particularly preferably, the liner of the present invention comprises the entire getter material in a non-stick release layer.

  In a preferred embodiment, the liner of the present invention comprises a getter material in the non-stick release layer and the getter material present in the non-stick release layer has an average particle size of less than 500 nm. This is beneficial. This is because, in this case, the tack-free properties are only affected to a minimum extent and any desired transparency is more effectively retained. In addition, a particularly smooth release layer surface is produced, so that, for example, less permeate from ambient air is included during lamination to the surface of the adhesive tape. Particularly preferably, the getter material present in the non-stick release layer has an average particle size of less than 200 nm. In this case, the above characteristics are shown in a much improved manner.

  In a further preferred embodiment, the liner of the present invention comprises a getter material in the non-stick release layer and the getter material present in the non-stick release layer has an average particle size of 500 nm to 50 μm. This is beneficial. This is because, in this case, the incorporated getter can give the release layer a rough surface, thereby reducing the contact area between the adhesive and the liner, and having a positive effect on the release properties. is there. This is especially true for silicone release layers. Thus, particularly preferably, the liner of the invention has a non-stick silicone release layer with a getter material, and the getter material present in the non-stick release layer has an average particle size of 500 nm to 50 μm.

  In order to increase the bonding capability of a release layer filled with getter material, it is advantageous to increase the thickness of the layer beyond the range commonly used for release effects. An advantageous thickness of the getter-filled release layer is 5 μm to 10 μm. This is because in this case, it is possible to reduce the consumption of the release material, that is, the cost. However, a layer thickness of 10 μm to 100 μm is particularly advantageous. This is because in this case it is possible to achieve a rapid increase in the binding capacity to the permeate.

  The non-tacky release layer preferably contains 0.5% to 10% by weight of getter material based on the total weight of the non-tacky release layer. It has been found that within this fractional range, good getter capacity can be achieved on the one hand, and on the other hand, the delamination properties of the layer are very slightly affected.

  In another preferred embodiment, the liner of the present invention includes a getter material in the carrier layer. Particularly preferably, the liner comprises the entire getter material in the carrier layer. In this case, any adverse effect on the efficiency of the release layer is advantageously eliminated. The carrier layer preferably comprises 5% to 20% by weight of getter material, based on the total weight of the carrier layer. This is beneficial because the exposure of the carrier layer to the environment is more direct than the release layer, for example, so that a greater amount of permeate can act on the carrier material.

  The getter material can also be dispersed in a layer of a liner structure intended to contain the getter material and not acting as a release layer or carrier layer. For example, this can be a varnish layer or printing ink in which getters are present in dispersed form. However, an absorbent layer such as a sheet-like woven structure impregnated with a fluid getter material is also suitable.

  In one particular embodiment, the liner of the present invention comprises not only the carrier layer, but also an intermediate layer disposed between the carrier layer and the non-stick release layer, and the getter material is present in the intermediate layer. This has the advantage that not only the carrier layer but also the release layer can be optimized with respect to their carrier and emission properties, respectively, and are not adversely affected by getter particles in their function.

  The intermediate layer preferably comprises an adhesive as a continuous phase. “Continuous phase” in this context means the material of the layer in which the getter particles are dispersed. With the adhesive as the continuous phase of the intermediate layer, it is possible advantageously to produce an assembly between the release layer and the carrier layer or other layers of the liner, for example in a liner structure.

  The intermediate layer containing the getter material can be discontinuous in shape, in other words, perforated, for example, composed of a dome or grid, and the getter is dispersed in the adhesive material of the dome or grid Yes. A perforated layer has the advantage that allowed permeate can pass through the layer more easily and the permeate to be bound is taken up.

  Particularly preferably, the liner is provided with an additional carrier layer and an intermediate layer comprising a getter material is arranged between the two carrier layers. Highly preferably, the intermediate layer comprises the adhesive as a continuous phase.

The structure of the liner of the present invention having an intermediate layer containing a getter material is shown by way of example in FIGS. Here the reference signs have the following meanings:
10: Carrier layer 20: Intermediate layer 30 filled with getter material, preferably with adhesive as continuous layer 30: Non-tacky release layer 40: Additional carrier layer, preferably an adhesive that forms the continuous phase of the intermediate layer Or there is no fundamental limitation in the selection of the adhesive compound. However, preferably a laminating adhesive is used. Particularly preferably, the adhesive is a pressure sensitive adhesive or an activatable adhesive or an activatable pressure sensitive adhesive.

  Liquid adhesives can be used as well. Intended are the well-known one-part and two-part reactive adhesives, both of which include thermosetting and radiation curable systems.

The adhesive preferably has a low permeability for the permeate to be immobilized. In the case of water vapor as the permeate, the water vapor transmission rate (WVTR) is preferably less than 100 g / (m ^{2 *} d), more preferably 50 g / (m ^{2 *} d), based on an adhesive thickness of 50 μm. Is less than. Here, WVTR is measured at 38 ° C. and 90% relative humidity in accordance with ASTM F-1249. This allows the adhesive layer to be produced and the liner assembly laminated under conventional ambient conditions without the getter material being largely saturated with permeate.

  When pressure sensitive adhesives are used, the polymer base is preferably from polyacrylate, polyester, polycarbonate, natural rubber and / or synthetic rubber, more preferably synthetic rubber based on styrene block copolymers. Become.

In configurations that include a first carrier material and an additional carrier material, the carrier material that is located near the permeate is preferably immobilized in order to rapidly penetrate the permeate into the intermediate layer that includes the getter material. High permeability to permeate. In the case of water vapor as the permeate, the water vapor transmission rate (WVTR) is preferably 50 g / (m ^{2 *} d), more preferably 200 g / (m ^{2 *} d), based on the thickness of the carrier material. . Here, WVTR is measured at 38 ° C. and 90% relative humidity in accordance with ASTM F-1249. Thus, for example, a polymer film composed of a polar copolymer of ethylene, such as ethylene-vinyl acetate, polyurethane, cellulose acetate, polymethyl methacrylate, or polyvinyl alcohol, as a carrier material placed near the permeate. Especially suitable. Likewise, membranes that allow transport of permeate by porosity or perforation, such as paper from the sanitary products sector or micro-perforated polyethylene films, are also very suitable.

  In this type of configuration, it is further preferred that at least one (preferably both) of the two carrier layers has a low permeate content. In this way, sufficient saturation is available to protect the adhesive to be protected from the permeate, since substantial saturation of the getter material with the permeate present in the carrier material is prevented. Preferably, at least one of the two carrier layers (more preferably both carrier layers) has a permeate content of less than 5000 ppm, more preferably less than 1000 ppm before using the liner of the present invention. Here, the number in ppm indicates the relationship between the total weight of the permeate present and the total weight of the carrier layer. Permeate content can be determined by gas chromatography according to VDA 277, or in the case of water, DIN EN ISO 62 (gravimetric method, method 4) after storing the specimen for 24 hours at 23 ° C. and 50% relative atmospheric humidity Alternatively, it can be determined according to DIN 53715 (Karl Fischer titration).

In a further preferred embodiment, the material of the non-stick release layer is at least 100 g / (m ^{2 *} d), more preferably at least 500 g / (m ^{2 *} d), in each case based on a layer thickness of 50 μm. In particular, it has a permeability to water vapor. Water vapor permeability or barrier (WVTR) is measured at 38 ° C. and 90% relative atmospheric humidity according to ASTM F-1249. The permeation barrier for oxygen is measured according to DIN 53380 (part 3) at 23 ° C. and 50% relative atmospheric humidity. Here, the non-adhesive release layer material means a pure release layer material to which no getter is added. The permeate permeability of the release layer material is beneficial in that the permeate reaches the getter material particularly quickly and effectively, particularly from the adhesive side. Therefore, it is particularly preferred to use a silicone-based or acrylate-based release layer.

  Introducing the getter material into the layer in question can be accomplished by all of the techniques known to those skilled in the art. Here, the layer material, for example the release layer material or the carrier material, can be present in solution, in dispersion, in melt or as fluid.

  The total amount of getter material in the liner of the present invention can be 0.5 mass% to 95 mass% based on the total weight of the layer containing the getter material. This amount is substantially dependent on the desired uptake capacity for the permeate in question.

  For example, if only a low uptake capacity is required, it may be sufficient to use a small amount of getter material with a low uptake capacity. Thus, in a preferred embodiment, the liner comprises 0.5 wt% to 5 wt% getter material, based on the total weight of the layer comprising the liner getter material. In this case, the thickness and area of the matrix containing the desiccant can advantageously be situated at the respective lower limit.

  However, if a very high uptake capacity is required for the liner part, it is necessary to use a getter material with a relatively high getter material content and a matrix containing a getter material that should also have a high uptake capacity It is. However, getter materials with low uptake capacity can be used if desired from a cost and compatibility standpoint. Thus, in a further preferred embodiment of the liner of the present invention, the liner comprises 60% to 95% by weight getter material, based on the total weight of the liner layer comprising the getter material.

  Getter materials with high uptake capacity (maximum obtainable permeate weight> 25% of getter weight) are preferred. This is because the amount of getter can be kept low by this means. In this case, the uptake capacity is stored at 23 ° C. and 50% relative atmospheric humidity for water vapor as the permeate or in the case of other gaseous permeates for 100 hours in a saturated atmosphere at 23 ° C. for 100 hours. Will be decided after. The permeate content of the getter after storage can be determined by gravimetry. In terms of uptake capacity, the getter material is preferably selected from the group consisting of copper sulfate, calcium oxide and calcium chloride.

  In a preferred embodiment, the liner of the present invention consists of a carrier layer and a non-stick release layer and therefore contains exclusively these two layers. This is beneficial because such liners are more flexible than multilayer liners and are easier to achieve adhesion between two layers than multilayer liners. Furthermore, this type of liner can be manufactured using less material. For liners consisting only of a release layer, this embodiment has the advantage that a particularly suitable material can be selected for each function, since the release function and the mechanical stabilization function exist in two separate layers. .

  In a further preferred embodiment, the liner of the present invention comprises a carrier layer, a non-stick release layer, and a primer layer disposed between the carrier layer and the release layer. The primer layer (also) preferably comprises a getter material. Particularly preferably, the primer layer comprises all of the getter material present in the liner and is thus configured as the only layer in the liner containing the getter material.

  The liner of the present invention is preferably transparent. That is, the transmittance measured according to ASTM D1003-00 (Procedure A) is greater than 50%, more preferably greater than 75%. A transparent liner allows the adhesive tape to be more easily placed when applied.

  Particularly preferably, the liner of the present invention is opaque to UV light. That is, the transmittance in the wavelength range of 200 to 400 nm measured according to ASTM D1003-00 (Procedure B) is less than 25%, preferably less than 10%. In UV impermeable liners, the adhesive can be protected from changes (eg, chemical reaction, aging, cross-linking) as a result of the effects of UV light.

  The present invention further provides an adhesive that is at least one side and at least partially covered by the liner of the present invention. This adhesive is preferably a pressure sensitive adhesive or an activatable adhesive, in particular an activatable pressure sensitive adhesive.

  A pressure sensitive adhesive (PSA) is an adhesive in which a specified film that is dry at room temperature permanently retains adhesion and adhesion. Even at relatively low pressure, the PSA can be permanently bonded to the substrate and can be separated from the substrate again after use with substantially no residue. Adhesive properties of adhesives are based on their adhesive properties, and their re-separability is based on their cohesive properties.

  According to the invention, it is possible to use, for example, all PSAs known to those skilled in the art, i.e. for example acrylates and / or methacrylates, polyurethanes, natural rubber, synthetic rubbers; for example polybutadiene, polyisoprene and Styrene block copolymers having elastomeric blocks composed of unsaturated or hydrogenated polydiene blocks, such as copolymers of both, and additional elastomeric blocks known to those skilled in the art; polyolefins, fluoropolymers and / or Examples include those based on silicone.

  When referring to acrylate-based PSAs herein, unless explicitly stated otherwise, the term includes, without explicit reference, methacrylate-based PSA and acrylate-methacrylate-based PSA. Is included. Similarly, suitable for use in the present invention are combinations and mixtures of two or more base polymers and adhesives to which tackifying resins, fillers, age inhibitors and crosslinking agents have been added. However, the description of these additives is merely an example, and is not limited to the interpretation thereof.

  PSA based on styrene block copolymer, polybutylene, polyolefin or fluoropolymer is preferred. This is because these adhesives are known not only to have a high permeability barrier to water vapor, but also to have a low water content.

  An activatable adhesive is considered to be an adhesive system in which bonding is achieved as a result of energy input, for example by actinic radiation or heat.

  Thermally activated bond adhesives can in principle be divided into two categories: thermoplastic heat activated bond adhesives (hot melt adhesives) and reactive heat activated bond adhesives (reactive adhesives). is there. Likewise included are adhesives that can be assigned to both categories, ie reactive thermoplastic heat-activated bond adhesives (reactive hot melt adhesives).

  Thermoplastic adhesives are based on polymers that undergo reversible softening when heated and resolidify during cooling. Thermoplastic adhesives found to be advantageous are in particular polyolefins and copolymers of polyolefins, as well as their acid-modified derivatives, ionomers, thermoplastic polyurethanes, polyamides and polyesters and their copolymers, and styrene. It is based on block copolymers such as block copolymers.

  In contrast, a reactive heat-activated bond adhesive includes a reactive component. The latter component is recognized as a “reactive resin” where heating initiates the cross-linking process and ensures a durable and stable bond after the end of the cross-linking reaction. Such an adhesive also preferably includes an elastic component, such as a synthetic nitrile rubber or styrene block copolymer. Such elastic components, due to their high flow viscosity, give the heat-activatable adhesive a particularly high dimensional stability even under uniform pressure.

  Similarly, radiation activated adhesives are based on reactive components. The latter component can include, for example, a polymer or reactive resin that initiates a crosslinking process upon irradiation and ensures a durable and stable bond after completion of the crosslinking reaction. Such an adhesive also preferably includes an elastic component as listed above.

  It is preferred to use activatable adhesives based on epoxides, oxetanes, (meth) acrylates or modified styrene block copolymers.

  However, in principle, if all adhesives that can be configured in the form of films and are known in the prior art are described for sealing precision electronic devices, they are preferred. The adhesive preferably has a permeate content of less than 1000 ppm, more preferably less than 100 ppm, before contacting the liner of the present invention. Here, this number in ppm refers to the relationship between the total weight of permeate present and the analytical weight of the adhesive. The permeate content can be determined by gas chromatography according to VDA277 or, in the case of water, at 23 ° C. and 50% relative atmospheric humidity according to DIN EN ISO 62 (gravimetric method 4) or DIN 53715 (Karl Fischer titration). It can be determined after storing the specimen for 24 hours. In the case of the permeate content of the adhesive described here, the capacity of the getter material in the liner is not that much permeated by the permeate diffusing from the adhesive, but this liner is a permeate from the environment. It is better to be able to fulfill its function as a cover to protect from.

The adhesive preferably has a low permeability for the permeate to be immobilized. In the case of water vapor as the permeate, the water vapor transmission rate (WVTR) is preferably less than 50 g / m ² per day, more preferably less than 20 g / m ² per day, based on an adhesive thickness of 50 μm. It is. Here, WVTR is measured at 38 ° C. and 90% relative atmospheric humidity according to ASTM F-1249, and oxygen transmission rate (OTR) is measured at 23 ° C. and 50% relative atmospheric humidity according to DIN 53380 (Part 3). The

  As a result of the low permeability at the adhesive part, less permeate diffuses from the environment through the adhesive into the liner containing the getter material, so it can perform its function over a long period of time or less The amount of getter material provided can thereby reduce material usage and save costs.

  The adhesive of the present invention preferably takes the form of an adhesive tape. That is, the adhesive tape comprises at least one layer of PSA or activatable adhesive or in particular at least one layer of activatable PSA. The adhesive tape can also include additional layers, such as an adhesive layer or one or more additional layers of carrier material.

  The adhesive tape preferably comprises only one layer of adhesive (adhesive transfer tape). This is because it keeps the configuration simple and allows the number of possible permeates that need to be taken into account to be kept small as a result of the relatively low material diversity. Furthermore, there is no material to prevent permeate diffusion from the adhesive tape to the getter-containing liner, allowing the adhesive tape to have no permeate in a particularly efficient manner.

  The thickness of the adhesive tape covers all conventional thicknesses, in other words, can range from about 3 μm to 3000 μm. A thickness of 25-100 μm is preferred. This is because bond strength and handling properties are particularly beneficial within this range. A more preferable range is a thickness of 3 to 25 μm. This is because within this range, the amount of material that permeates through the bond line can be minimized by the small cross-sectional area of the bond line when applying encapsulation. Moreover, it has surprisingly been found that such a small thickness of adhesive tape can effectively eliminate permeate through the getter-filled liner.

  Particularly preferred is an adhesive transfer tape. This is because in this case there is no carrier material to prevent diffusion of the permeate from the adhesive tape to the getter-containing liner, so that the adhesive tape can be separated from the permeate in a particularly efficient manner.

  The present invention further provides a method for protecting the adhesive from permeate, wherein the method comprises coating at least one side and at least a portion of the adhesive with the liner of the present invention.

  For example, to produce an assembly of the adhesive tape and liner of the present invention, the adhesive tape carrier or liner is either from a solution or dispersion or 100% (eg as a melt) with the preferred PSA of the adhesive tape. One side is coated or printed, or the assembly is produced by coextrusion. Another option is to form the assembly by transferring a layer of adhesive or liner by lamination. One or more layers of the adhesive can be crosslinked by heating or high energy radiation.

  This operation is preferably performed in an environment in which the specific permeate is present only in low concentrations or almost no. An example that may be mentioned is a relative atmospheric humidity of less than 30%, preferably less than 15%.

  Self-adhesive composition used to optimize properties and tackifiers (resins), plasticizers, fillers, pigments, UV absorbers, light stabilizers, anti-aging agents, cross-linking agents, cross-linking accelerators It is possible to blend with one or more additives such as agents or elastomers.

The amount of adhesive layer is preferably 10 to 120 g / m ² , preferably 25 to 100 g / m ² , where “amount” is after any removal of water or solvent that can be carried out. Means the amount.

  The present invention further provides the use of a getter material capable of sorbing at least one permeable substance to provide a liner for protecting an adhesive.

  Of course, the adhesive to be protected can be provided with the liner of the invention on both sides.

  Further provided by the present invention is a method for encapsulating an optoelectronic component and / or an aerobic curable adhesive and / or a moisture curable adhesive covering at least one side and at least a portion of an adhesive tape. For the use of the liner of the invention.

  The invention further provides the use of a liner according to the invention, preferably comprising calcium oxide, metallic calcium and / or cobalt chloride as a getter material, to indicate the permeate content of the adhesive covered with the liner. This indication is achieved by a change in the optical properties of the getter material present in the liner. That is, for example, as water binding proceeds, the color of calcium oxide changes from white to transparent. Similarly, metallic calcium loses its metallic opaque appearance and becomes increasingly transparent. Thus, to the extent that the getter material can still be recognized with an unused appearance, this indicates that the permeate has not yet been diffused at all to the adhesive to be protected, or at best it has diffused little. Can be interpreted.

Examples Various liners filled with getter material were produced. These were laminated to various adhesive tapes with a laboratory roll laminator in a controlled climate room at 23 ° C. and 50% relative atmospheric humidity.

Adhesive tape:
To produce adhesive tapes, various pressure sensitive adhesive agents (PSAs) can be applied to conventional liners that are not in accordance with the present invention and not impervious to permeation using a laboratory coating apparatus. This liner was applied from solution to ADI I38 UV1 made by Mondi, with an aluminum foil carrier) and the coating was dried. The thickness of the adhesive layer after drying was 25 μm in each case. Drying was in each case carried out in a laboratory drying cabinet at 120 ° C. for 30 minutes.

  The adhesive was stored for 72 hours at 23 ° C. and 50% relative atmospheric humidity in one case and 72 hours at 60 ° C. and 95% relative atmospheric humidity in the other case. The moisture content of the adhesive was each determined prior to lamination to the liner containing the getter material.

  In the case of adhesive tapes 1 and 2, the specimen was likewise dried at 120 ° C. for only 5 minutes. The residual solvent content was measured immediately after drying.

Determination of residual solvent content:
The residual solvent content of the adhesive was measured by headspace gas chromatography. A sample area with a size of about 12.5 cm ² was cut from the sample, bonded to a metal wire spiral, and transferred to an about 22 mL glass headspace vial.

  Samples were measured using a Dani GC 86.10 gas chromatograph with a QUMA QHS S40 autosampler. Samples were conditioned at 120 ° C. for 1 hour in the instrument. Detection was performed with a flame ionization detector (FID). GC peaks were quantified against an external standard.

Silicone release system filled with getter material The release system is about 75 μm thick with a polyester carrier (Lumirror 60.01 / 75; hereinafter referred to as PET) having a thickness of about 75 μm and an inorganic barrier layer coating. It produced by apply | coating the peeling type | system | group compound shown below using the application unit for laboratories on a polyester film (Toppan printing GX-PF; hereafter, barrier-PET). The coating amount was 2 g / m ² . After application, the release system was crosslinked for 30 seconds in a forced air oven at 160 ° C.

  The silicone used is an addition crosslinkable silicone system manufactured by Wacker. 9.75 g DEH915 (polydimethylsiloxane functionalized with vinyl groups), 0.33 g V24 (methylhydrogen polysiloxane) and 0.08 g Kat OL (platinum catalyst, also known as “Calstead catalyst”) Mixed). Both raw materials were previously dried at 23 ° C. with zeolite beads (supplier Sigma-Aldrich molecular sieve 4 cm).

  The dried silicone system was mixed with various getter materials in various proportions, and the mixture was subsequently homogenized and immediately used for coating. After drying, the coated liner was bonded to a vacuum pouch made from a permeation resistant film laminate (polyester film-aluminum foil sealed adhesive film) and was not removed until just before use.

A polyolefin release liner film filled with getter material was produced by flat film coextrusion. This consisted of a 50 μm base layer and a 10 μm outer layer. The base layer was 91.3% (w / w) polypropylene block copolymer Novolene 2309L (BASF, 230 ° C. and 2.16 kg, melt index 6 g / 10 min, ethylene content about 6.5% (w / w )), 8.4% (w / w) titanium dioxide and 0.3% (w / w) HALS stabilizer Tinuvin 770.

  The outer layer consists of 85% ethylene multiblock copolymer Infuse D9107 (The Dow Chemical Company, d = 0.866 g / cm3) and 15% polyethylene LD251 (ExxonMobil, d = 0.9155) and below It was made of the getter material shown in FIG. The outer layer material was kneaded inline by flat film extrusion in a twin screw extrusion unit manufactured by Coperion (d = 25 mm, L / d = 37), and sent to the feed block of the coextrusion unit by an insertion melt pump. The getter material was fed to the twin screw extruder using a side feeder after melting and homogenization of the polymer components.

  The liner thus produced was dried and then bonded to a vacuum pouch made from a permeation resistant film laminate (polyester film-aluminum foil sealing adhesive film) and not removed until just before use.

Getter Material Filled Carrier Layer for Release Coating Dow polypropylene polymers Inspire D404.01 and 7C06 were mixed in a 1: 1 ratio and extruded. The film was produced with a Coperion twin screw extrusion unit (d = 25 mm, L / d = 37) having a flange-connected flat die in one layer, followed by a cooling roll station and a single stage short gap stretching unit. The getter material was fed using a side feeder after melting and homogenizing the polymer components.

  The die temperature was 235 ° C. The cooling roll temperature and stretching roll temperature were set so as to maximize the crystallinity of the film before and after the stretching operation. The draw ratio was 1:10. The film had a final thickness of 100 μm.

  The carrier thus produced was coated as described above with a dry silicone system (without further addition of getter) immediately after production.

  After silicone-based crosslinking, the coated liner was bonded to a vacuum pouch made from a permeation resistant film laminate (polyester film-aluminum foil sealed adhesive film) and was not removed until just before use.

  For application to thin layers (eg release layers), the getter materials G2, G3, G6 and G7 were crushed and appropriately sorted so that no particles larger than the layer thickness were present. After the grinding operation, these particles were regenerated by heat treatment in a manner known to those skilled in the art. Where necessary, the release layer or carrier layer material was filtered as appropriate after the introduction of the getter material and during or before the production of the layer.

Measurement of Release Behavior The release liner described above was bonded to a strip of test adhesive tape tesa® 7475 each having a width of 20 mm and a length of 300 mm. The tesa® 7475 test tape comprises a 40 μm thick PVC carrier coated with 95 g / m ² of a resin modified pressure sensitive acrylate adhesive.

For each sample, three laminates of liners with test tape tesa® 7475 were stored for 24 hours at a given pressure and temperature. The storage temperature was 70 ° C. for tesa® 7475 test tape. The pressure was 4 N / cm ² .

  The sample was then stored for 2 hours in an acclimatization chamber at 23 ° C. and 50% relative atmospheric humidity, after which the peel behavior was similarly determined at 23 ° C. and 50% relative atmospheric humidity at a tensile rate of 300 mm / min by tensile test. Measured with The reported peel force is an arithmetic average of three samples.

Measurement of water content The water content was determined according to DIN 53715 (Karl Fischer titration). The measurement was performed with a Karl Fischer coulometer 851 linked with an oven sampler (oven temperature 140 ° C.). Triplicate determinations were performed with an initial mass of approximately 0.3 g each time. The water content reported is the arithmetic mean of the measurements.

  Table 1 gives an overview of the manufactured getter material-containing liners and their peel forces.

  The peel force found indicates that all of the manufactured liner can be used as is. The peel force for a polyolefin release layer is in the range known for such layers.

For further investigation, a piece of adhesive tape approximately 100 × 100 mm ² in size was conditioned under various atmospheres as already described above, and immediately thereafter using a laboratory laminator at 23 ° C. and Lined with liner at 50% relative atmospheric humidity. The laminate thus produced was stored for 72 hours under the following atmosphere:
Atmosphere A: 23 ° C., 50% relative atmospheric humidity atmosphere B: 23 ° C., 95% relative atmospheric humidity atmosphere C: 23 ° C., sealed with vacuum permeation-proof packaging

  Finally, the water content and the toluene content in the adhesive of the test piece were confirmed. Here, the specimen was taken from the center of the specimen area in order to avoid the edge effect. The results are summarized in Table 2.

  These results show that the liner of the present invention is suitable for holding the permeate away from the adhesive tape (Examples 1-13, 27-30, 35-38, 43-46 and 51-51). 55 and comparison with Comparative Examples C1 to C4). Here, a surprising finding is that the liners (L11 to L14) in which the getter material is dispersed in the carrier exhibit higher efficiency.

  Furthermore, it is also useful when the carrier material itself exhibits a high barrier property against the permeate (L15 to L16). This is because, in this case, in the experiment, the getter volume is sufficient to actually capture the entire amount of permeate.

  Surprisingly, the liner of the present invention is also suitable for removing permeate from the adhesive tape (Examples 14-26, 31-34, 39-42, 47-50). Also surprisingly, the liner (L11-L14) in which the getter material is dispersed in the carrier is higher despite the fact that the layer containing the getter material is not in direct contact with the layer of adhesive. It was also found to show efficiency.

  In a further example, a liner of the type shown in FIG. 2 was used (see Table 3).

  As an assembly of the release layer and carrier material, Silphan S12 M 2R13017 (12 μm PET), Silphan S36 M372 (36 μm PET) available from Siliconetechnica, Italy and KS900 White 52B20 available from Laufenberg, Krefeld, Germany ( A conventional liner of the paper type was used.

  As an additional carrier material, a BOPP film having a thickness of 36 μm manufactured by Pao-Yan of Taiwan and a laminate of an aluminum foil and a BOPP film manufactured by Novellis of Berlin, Germany were used.

  The getter material was incorporated into the adhesive solution by a dissolver. The adhesive was then applied to the second carrier material using a laboratory applicator and allowed to dry. Thereafter, conventional liners were laminated on the getter-filled layer of adhesive with their non-tacky side using a laboratory laminator. Thereby, a getter material filling liner was completed.

For further investigation, the adhesive tape part of the adhesive with a size of about 100 × 100 mm ² was conditioned in atmosphere A for 24 hours as already explained above, and immediately after that the laboratory laminator was turned on Used and lined with a liner at 23 ° C. and 50% relative atmospheric humidity. The laminate thus produced was stored in the atmosphere C for 14 days. Subsequently, the specimens were removed from their packaging in a glove box (atmosphere: water vapor <5 ppm, oxygen <1 ppm) and the adhesive was immediately sealed in each case in a glass container for the purpose of determining the water content. The results are shown in Table 4.

  These results show that the dryness of the protected adhesive is surprisingly low as compared to siliconized paper as it contains permeate (in this case water) and, as with PET. It can also be achieved with membranes (paper and PET) that only show permeate permeability. Even more surprisingly, the high loading of the getter material-containing layer does not automatically result in an improvement in the drying effect (compare Examples 60 and 65 with Comparative Examples 59 and 64, respectively).

  Thus, as shown herein, the liner of the present invention can be easily obtained from conventional liners by adding a layer comprising a getter material on the carrier material side of the liner. Comparative Example C11 shows a surprisingly high activity of a getter material-containing liner according to this preferred configuration. The low water loss in this comparative example can be attributed to the specimen prepared in the glove box. This is because, due to the high moisture content of the adhesive under investigation, drying has already begun by dry glove box conditions.

10: Carrier layer 20: Intermediate layer filled with getter material, preferably with adhesive as a continuous layer 30: Non-tacky release layer 40: Additional carrier layer

Claims (13)

A liner for protecting an adhesive, comprising a non-tacky release layer comprising at least one silicone system and at least one getter material capable of sorbing at least one permeable substance, The getter material is present as a dispersed phase in at least one layer of the liner, the getter material from the group consisting of calcium oxide, calcium sulfate, calcium chloride, silica, carbodiimide and zeolite and a mixture of two or more of the above substances. Selected, liner. The liner of claim 1, wherein the silicone system is a crosslinkable silicone system. The liner according to claim 1 or 2, wherein the getter material is selected from the group consisting of calcium oxide, calcium sulfate, calcium chloride and zeolite and a mixture of two or more of the above substances. The getter material, with 1% by volume are many being present in the form of particles having a particle size distribution of greater than average layer thickness of the layer containing the getter material, according to any one of claims 1 to 3 Liner. The getter material, characterized in that at least 10% by volume is present in the form of particles having a particle size distribution of greater than average layer thickness of the layer containing the getter material, according to any one of claims 1-4 liner. The liner includes not only a carrier layer but also an intermediate layer disposed between the carrier layer and the non-adhesive release layer, and the getter material is present in the intermediate layer. The liner according to any one of to 5 . The liner according to claim 6 , wherein the intermediate layer includes an adhesive as a continuous phase. The liner according to claim 6 or 7 , wherein the liner includes an additional carrier layer and the intermediate layer is disposed between the two carrier layers. An adhesive tape at least partially covered with a liner according to any one of claims 1 to 8 on at least one side. The adhesive tape of claim 9 , wherein the adhesive prior to contacting the liner has a permeate content of less than 1000 ppm. 9. The liner of any one of claims 1 to 8 , and at least one side of the adhesive tape and / or at least one side of the method for encapsulation of optoelectronic components and / or aerobic curable adhesives and / or moisture curable adhesives. Use for partial coating. Use of a liner according to any one of claims 1 to 8 to indicate the permeate content of an adhesive covered with the liner. Use of a getter material capable of sorbing at least one permeable substance for providing a liner according to any one of the preceding claims for protecting an adhesive.

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